Developing the Concept of the Personal Computer

While the Altair 8800 may have been the first commercially successful personal computer as we now understand the term, by most definitions, it wasn't the really the first PC, and it certainly didn't create the concept.

40 years ago this month, Popular Electronics, a Ziff Davis publication, ushered in the era of the personal computer with its cover story on the Altair 8800. Over the next few days, I'll be posting a number of pieces describing the steps that went into setting the stage for the Altair and the development of the machine itself.

While the Altair 8800 may have been the first commercially successful personal computer as we now understand the term, by most definitions, it wasn't the really the first PC, and it certainly didn't create the concept.

The concept of a personal computer goes back a lot earlier, at least to an influential article by Vannevar Bush entitled "As We May Think," which appeared in the July 1, 1945 edition of The Atlantic.

In this article, he describes the mechanization of all sorts of human processes, and talks about "a future device for individual use," in which someone could store all of his or her books, records, and communications. He called this device a "memex" because it functions as a supplement to memory. And while the details of the device he imagined—microfilm, dry photography, and keyboard codes, for instance—seem hopelessly outdated, the concept—a way to store, retrieve, and present all sorts of information—is quite clearly a personal computer.

By the dawn of the 1970s, a lot of the ingredients that would later be mixed together to create the PC were falling into place. Among larger systems, there was a trend toward "minicomputers," machines that were notably smaller than the big "mainframes" of the time, exemplified by the IBM 360. Instead, the industry saw a new crop of smaller computers—from companies such as Digital Equipment Corp. (DEC), Data General, Hewlett-Packard, and Wang Laboratories. These were generally still relatively expensive machines—DEC's popular PDP-8 started at $16,000. In this period, they ran first on discrete transistors and later on smaller integrated circuits but not yet microprocessors, which were just entering the scene.

It's easy to suggest that over time these minicomputers would have just gotten smaller and become personal computers. Indeed, there's a popular story of DEC co-founder and CEO Kenneth Olsen saying as late as 1977 that "there is no reason for any individual to have a computer in his home." While there is a lot of reason to believe that quote was taken out of context, it is true that DEC and the other minicomputer makers of the day failed to create smaller versions of their machines aimed at individual users until after the personal computer market as we know it was already up and running. (Indeed, in his book The Innovators, Walter Isaacson says that at a DEC operations committee meeting in May 1974 where the company was discussing creating a smaller version of the PDP-8, Olsen said, "I can't see any reason that anyone would want a computer of his own.")

The Silicon Valley Connection But at the same time, various groups of people near Palo Alto in California's Santa Clara Valley (not yet broadly known as Silicon Valley) were talking about taking computers away from big companies and making them more useable by individuals.

Indeed, by 1972, Stewart Brand, editor of the Whole Earth Catalog, had written an influential article in Rolling Stone entitled "Spacewar," which started with the phrase: "Ready or not, computers are coming to the people."

Brand continued by saying, "That's good news, maybe the best since psychedelics," and indeed in his book What the Dormouse Said (2006, Penguin Books), John Markoff argues that the Sixties counterculture—a liberal worldview associated with sex and drugs—was crucial in setting up the beginnings of the personal computer revolution.

Doug Engelbart and NLS Perhaps most influential of the early pioneers was Douglas Engelbart, who was talking about the "man-machine interface," or the user interface as it would eventually be called, as early as 1961. At the Stanford Research Institute (later known as SRI), he created what would become the Augmented Human Intellect Research Center or the Augment project. He received funding in part from Robert Taylor, then of the Advanced Research Project Agency (ARPA), which would also fund the basic work that created what became the Internet. Within the Augment project, they created the oNLine System (NLS), which was designed to allow researchers to share information and store and retrieve documents in a structured electronic library.

This work eventually led to what Markoff calls "still the most remarkable computer technology demonstration of all time" at the Fall Joint Computer Conference in San Francisco on December 9, 1968. During this famous presentation, which became known as the "mother of all demos," where he showed off a variety of interactive computer technologies, including many things that were unheard of in computing at the time.

Engelbart started his demo by saying "the research program I'm going to describe to you is quickly characterizable by saying, if in your office you as an intellectual worker were supplied with a computer display backed up by a computer that was alive for you all day and was instantly responsive to every action you have, how much value could you derive from that?"

The NLS demo included everything from text editing (which was already somewhat standard) to windowing and the mouse, as well as more advanced items such as desktop video conferencing, hypertext, and dynamic file linking.

That was very different from the batch-mode mainframes that dominated computing at the time, which often relied on punch cards you submitted and reports that came back notably later. Engelbart would be called the "father of the mouse," but more importantly, his software demo would prove an inspiration for a generation of personal computers.

The Home Information Terminal At around the same time, John McCarthy's Stanford AI Lab (SAIL) was another major center of computer research. McCarthy, too, was thinking about what people could do with computing power, although he was more focused on connecting terminals to a larger computer, using a system called time-sharing. (Today, we would think of this as a server with dumb terminals, and it's really not all that different in concept from cloud computing.)

In a 1970 paper called "The Home Information Terminal," McCarthy described a system that is remarkably close to today's vision of a PC user connected to the Internet:

"Visionaries have often proposed that homes be equipped with information terminals each consisting of a typewriter keyboard and a screen capable of displaying one or more pages of print and pictures. The terminal is to be connected by the telephone system to a time-shared computer which, in turn, has access to files containing all books, magazines, newspapers, catalogs, airline schedules, much additional public information not now kept, and various files personal to the user."

"Through the terminal the user can get any information he wants, can buy and sell, could communicate with persons and institutions, and process information in other useful ways. Such a system has never come about because it costs too much, but with each advance in technology, it becomes more feasible."

PARC: The DynaBook and the Alto In the early 1970s, many of the best ideas about what would become personal computers came out of Xerox's Palo Alto Research Center (PARC). One of the leaders there was Robert Taylor, who at ARPA had helped fund Engelbart and was one of the leaders in the creation of the ARPAnet. He helped recruit Alan Kay from SAIL, and Kay would go on to be one of the most influential figures in the development of the modern PC.

Kay's concept was for a portable computer the size of a notebook, weighing no more than 4 pounds, having 8K of memory, and costing less than $500. Indeed, in concept, it's a lot like today's Internet-connected notebook computers, although as the modern microprocessor had yet to be created, he described it as being built of "cheap LSI components." Kay called this a DynaBook and described it in a paper called "A Personal Computer for Children of All Ages," published in August 1972.

In this paper, he describes how two students named Beth and Jimmy could use such a machine for playing games ("Spacewar"), an online library of knowledge (similar to Wikipedia or maybe Google) and for math and drawing, while Beth's father could use it for research, typing, and downloading books.

Perhaps overestimating the technology a bit, in the paper he says: "It is now within the reach of current technology to give all the Beths and their dads a 'DynaBook' to use anytime, anywhere as they may wish. Although it can be used to communicate with others through the 'knowledge utilities' of the future such as a school 'library' (or business information system), we think that a large fraction of its use will involve reflexive communication of the owner with himself through this personal medium, much as paper and notebooks are currently used."

In other words, he was describing a connected personal computer. In 1972, Kay knew such a machine wasn't quite possible, saying the three biggest "handwaves" in his scenario were the flat-screen, low-power display, the price, and his guess on how much could be done on an unconnected 8K machine.

Since building a DynaBook in 1972 was impossible, Kay instead turned his attention to building what he called a "Minicom"—and in May of that year, at a meeting of the PARC Computer Science Laboratory, he sketched out the idea of a personal computer configured out of a Data General Nova connected to a 9-inch Sony black-and-white cathode-ray display. Taylor had been trying to build a "display based computer," and in August, PARC's Chuck Thacker and Butler Lampson offered to build the machine. This would turn out to be called the Xerox Alto.

The Alto has a mouse and a keyboard, and most innovatively for the time, a fully bitmapped display, which meant it could display graphics. That allowed it to be the first machine to run a graphical user interface (GUI), which would later become the standard in all computers. When the Alto was first demonstrated in April 1973, it started with an image of the first page of Winnie the Pooh and then a graphic of Cookie Monster holding the letter "C." (The concept of the GUI would eventually be popularized roughly a decade later by the Apple Macintosh and Microsoft Windows.)

The first machines were planned to cost $10,500 each, though only a few were ever made, and Xerox wouldn't begin to make a commercial machine, the Xerox Star, until much later.

Over the next few years, the San Francisco Bay Area would see a number of people gathering to talk about the concept of the personal computer.

Among these were Bob Albrecht, who would found the People's Computer Company, which wasn't a computer company at all but rather an influential newsletter aimed at hobbyists and others with an interest in computers and technology.

Its manifesto, laid out in the first issue in October 1972 was clear: "Computers are mostly used against people instead of for people. Used to control people instead to FREE them. Time to change all that—we need a…People's Computer Company."

By that point, Alan Kay and the team at PARC were creating what today looks like a personal computer, and Douglas Engelbart was on the hunt for the personal computer. But for the most part, the machines that are in contention for "the first PC" were actually put together by people well outside of the Valley.

As Markoff described it, "the scientists at Xerox PARC were convinced they were inventing the future, and so in June 1975 when Larry Tesler walked in one day to tell them there was something important happening outside the research center, no one really paid any attention."

That something important was the start of what would become the PC revolution: Tesler was going to see a demo of the Altair 8800 at the Rickey's Hyatt House Hotel in Palo Alto. Silicon Valley would soon birth the Homebrew Computer Club and many of the early computers, but the first steps were to happen elsewhere.

For more information, see Andy Grove: The Life and Times of an American by Richard S. Tedlow (2006, Portfolio Hardcover), "The Birth of the Microprocessor" by Federico Faggin, The Chip by T.R. Reid (2001, Random House Trade Paperbacks), "Defining Intel: 25 years, 25 Events" (1993, Intel Corporation), A History of Modern Computing by Paul E. Ceruzzi (2003, The MIT Press), Inside Intel by Tim Jackson (1997, Harper Collins), The Intel Trinity by Michael S. Malone (2014, HarperBusiness), The Man Behind the Microchip by Leslie Berlin (2006, Oxford University Press), Microchip by Jeffrey Zygmont (2002, Basic Books), The New Alchemists by Dirk Hanson (1983, The Book Service Ltd), "Oral History on the Development and Promotion of the Intel 4004 Microprocessor," Computer History Museum, "Oral History on the Development and Promotion of the Intel 8008 Microprocessor," Computer History Museum, and The Real Revolutionaries (2012, Diamond Docs, iLine Entertainment).

Michael J. Miller's Forward Thinking Blog: forwardthinking.pcmag.com
Michael J. Miller is chief information officer at Ziff Brothers Investments, a private investment firm. From 1991 to 2005, Miller was editor-in-chief of PC Magazine, responsible for the editorial direction, quality and presentation of the world's largest computer publication.
Until late 2006, Miller was the Chief Content Officer for Ziff Davis Media, responsible for overseeing the editorial positions of Ziff Davis's magazines, websites, and events. As Editorial Director for Ziff Davis Publishing since 1997, Miller took an active role in...
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